Sowbugs reach up to ½ inch long.
Sowbugs are dark gray in color, have seven pair of legs and are made up of about ten lateral plates that overlap one another. They are related to pillbugs, but cannot curl up into a tight, round ball when disturbed.
Sowbugs, like pillbugs, are closely related to other crustaceans such as crabs, shrimp and crayfish. Like their oceanic relatives, they require areas of high moisture for survival. Sowbugs may live for up to two years, and they molt consistently throughout their lifetime. They are commonly found outdoors under mulch, compost, boards and stones. They often enter crawl spaces, damp basements and first floors of houses and usually enter through door thresholds, expansion joints, and voids of concrete block walls. Frequent sightings of these pests indoors means there are large numbers breeding close to the foundation.
Sowbugs eat decaying organic and vegetable materials, although they also may attack living plant tissues and turf, as well as fruits and vegetables.
Females have leaf-like growths at the base of some legs, which are brood pouches for holding developing eggs and embryos. Females produce a batch of around 25 eggs that hatch within a pouch on her ventral side. Females may have several broods each year.
Sowbugs and pillbugs are the only crustaceans totally adapted for living on land.